Efficiency of Selected Terpene-Based and Conventional Solvents in the Dissolution of Asphaltene Deposits

Abstract

Abstract The need for more efficient, cost effective, relatively high flashpoint, and environmental friendly organic solvent is crucial. Due to safety and environmental effects of the conventional aromatic solvents, efforts are being focused to search for more natural based products. A total of 14 terpene-based and conventional solvents have been examined to identify their dissolving power of asphaltene/organic sludge. The organic solvents vary in their compositions from xylene or conventional based solvents to the more environmental friendly compounds of terpene (green solvents). They also vary in their flash points from as low as 75°F tod as high as 200°F. The organic scale/sludge samples have been studied by thermogravimetric analysis (TGA), FT-IR, ESI-MS and asphaltene analyses. The analysis showed the contents of asphaltene, functional groups, saturation level and weigh loss of both deposits. Dissolution tests were conducted on both organic deposits using 11 terpene-based solvents and 3 conventional solvents. Dissolution tests were conducted at room temperature and 50°C with soaking times of 3 and 24 hours. The solubility of deposit A at most of the solvents was found to be lower than the solubility of deposit B due to variation in both deposits’ compositions. Even though the increase of the soaking time was found to be of positive impact, most of the dissolving occurred in the first few hours. This study results also revealed that the efficiency of the terpene-based organic solvents is a function of terpene concentration; however, increasing the terpene concentration would decrease the flash point, which is of a safety concern in warm climate countries, especially during high temperature seasons. The environmentally friendly terpene-based solvents displayed promising results and can be an alternative to conventional solvents.